1. Field of the Invention
The invention relates to a touch apparatus and a driving method thereof, and more particularly to an optical touch apparatus and a driving method thereof.
2. Description of Related Art
With the development of optoelectronic technology, the user's requirement may not be satisfied through controlling the computer and objects in the screen by using the mouse. Accordingly, a method more humanistic than the mouse is gradually developed. Among these humanistic methods, the touch method by using fingers is closest to the human experience in the daily life. Particularly, for elders and children unable to use the mouse smartly, they may touch with fingers easily. The advantage has been partially proved from the touch screen used in the automated teller machine (ATM).
Furthermore, in the conventional computer without being externally connected with the mouse, the cursor is usually controlled by the touch plate located beside the key-presses or the track point. However, for the user, one may control the cursor more smartly by using the mouse instead of the touch plate located beside the key-presses or the track point, but this issue may be overcome by using the touch panel disposed on the screen. Because the control method by using the touch panel is a direct control method, the user may control the objects by directly touching the screen. In this manner, when the touch panel is applied to the notebook, even under the condition that the mouse is inconvenient to be connected to the notebook, the user may still smartly operate by using the touch panel.
Currently, based on the design, a touch sensing panel may be generally categorized into a resistive touch sensing panel, a capacitive touch sensing panel, an optical touch sensing panel, an acoustic-wave touch sensing panel, and an electromagnetic touch sensing panel. Generally, in the resistive touch sensing panel, by the pressure of pressing a single point, the conductive layers originally separated are connected to each other, so that the conductive layers are conducted, thereby generating a voltage difference. By measuring and calculating the voltage difference, the touch position may be determined. In the capacitive touch sensing panel, the electric field is generated in the conductive layers. When the object, such as the finger, touches the touch sensing panel, a charge flow is generated, thereby generating a small capacitance difference. By measuring the capacitance difference, the touch position may be determined.